The flow characteristics of control valve are very important to product quality. For measuring the flow coefficient and flow curve accurately and all-rounding, we have designed a test system,which worked with PLC, it can measure the flow characteristics and resistance coefficient of control valve. The main purpose of this study was to bring out the work elements, design feature, and test software.The study we have performed showed that this test system is reasonable, easy to support entire automatic measurement with high precision and easy operation.